Wedding in the forest/at a park/in a barn

I live in Nassau County and my fiance and I want to do a budget wedding. We'd rather spend the money on a down payment for a house then blow $30-40,000 on a 5 hour party. We are looking to have a low key party at a park or similar outdoor space. A friend who is a caterer offered to cater for us so we just need to find a space. We can rent a tent for coverage in case of rain. Any thoughts?